Coding guidelines: Part A inpatient billing for malnutrition diagnosis codes

The following information provides billing guidelines for severe protein calorie malnutrition when billed during an inpatient admission.

Severe protein calorie malnutrition

Malnutrition is a broad term used to describe undernutrition.

Diagnosis is usually based on patient history with clinical indications documented in the medical record:

• To determine severity:
  • BMI, serum albumin, total lymphocyte count, CD4+ count, serum transferrin
• To diagnose complications and consequences:
  • Complete blood count (CBC), electrolytes, blood urea nitrogen (BUN), glucose, calcium, magnesium, phosphate
• Physical examination to include:
  • Measurement of height and weight
  • Inspection of body fat distribution
  • Anthropometric measurements of lean body mass
  • BMI calculated to determine severity
• History and clinical diagnosis:
  • Demonstrates risk for severe malnutrition
• Physical exam / clinical signs:
  • It can reveal the presence of several of the diagnostic characteristics of malnutrition such as weight loss or gain, fluid retention, loss of muscle or fat, and other signs of specific macro- and/or micronutrient deficiencies

Coders must keep the ICD-10-CM official guidelines for coding and reporting in mind when coding malnutrition.

For reimbursement, malnutrition must be identified, diagnosed, documented and treated by the physician while providing care for the primary illness.

Conditions that may support the diagnosis of severe malnutrition:

• Disorders that affect gastrointestinal (GI) function (interference with digestion, absorption or lymphatic transport of nutrients):
  • Pancreatic insufficiency
  • Enteritis
  • Enteropathy
  • Retroperitoneal fibrosis
  • Milroy disease
• Wasting disorders: catabolism causes cytokine excess, resulting in undernutrition via anorexia and cachexia (wasting of muscle and fat)
• Decrease in appetite or impairment of metabolism of nutrients:
  • Acquired immune deficiency syndrome (AIDS)
  • Cancer
  • Chronic obstructive pulmonary disease (COPD)
  • Renal and heart failure
• Conditions that increase metabolic demands:
  • Hyperthyroidism
  • Pheochromocytoma
  • Burns
  • Trauma
  • Critical illnesses

Signs may include:

• Weight loss:
  • 10% of body weight lost
  • Starved adults may lose up to 50% of their normal body weight
• BMI under 18.5
• Obvious significant muscle wasting, loss of subcutaneous fat
• Nutritional intake of < 50% of recommended intake for two weeks or more (as assessed by the dietician)
• Bedridden or otherwise significantly reduced functional capacity
• Weight loss of > 2% in one week, 5% in a month, or 7.5% in three months
• Include labs and clinical findings

ICD-10 codes for malnutrition 

When billing malnutrition codes for an inpatient hospital stay, hospitals should perform the DRG validation review process, review related coding review practices, as well as verify medical record documentation supports the malnutrition code billed on the claim.  

DRG validation is performed to ensure that diagnostic and procedural information and the discharge status of the beneficiary, as coded and reported by the hospital on its claim, matches both the attending physician's description and the information contained in the beneficiary's medical record. Reviewers shall validate principal diagnosis, secondary diagnoses, and procedures potentially affecting the DRG. 

(Not an all-inclusive listing)

Resources

Additional information 

CMS representatives have participated in multiple multi-stakeholder discussions regarding opportunities available to advance malnutrition care quality.

The Malnutrition Quality Improvement Initiative (MQii) is a project of the Academy of Nutrition and Dietetics, Avalere Health, and other stakeholders who provided expert input through a collaborative partnership. This initiative aims to advance evidence-based, high-quality and patient-driven care for hospitalized older adults who are malnourished or at-risk for malnutrition. 

• FY 2023 Hospital inpatient prospective payment system (IPPS) and long-term care hospitals (LTCH PPS) proposed rule - CMS-1771-P
• Global malnutrition composite score soon available for 2024 hospital reporting - MQii (malnutritionquality.org)

CMS guidelines:

• Medicare Program Integrity Manual, Pub. 100-08, Chapter 3 - Verifying potential errors and taking corrective actions, section 3.3.2.1.1.B “Progress notes and templates, guidelines regarding which documents review contractors will consider”

For additional information on the DRG validation review process:

• CMS IOM Pub. 100-08, Program Integrity Manual Chapter 6, section 6.5.3 "DRG validation review"

Additionally refer to:

• Master malnutrition definitions, coding rules | ACDIS
• Q&A: documenting and coding severe malnutrition | ACDIS
• Coding malnutrition in elderly patients (outsourcestrategies.com)
• Malnutrition, obesity and BMI: medical coding guidelines (outsourcestrategies.com)
• Hospitals overbilled Medicare $1 billion by incorrectly assigning severe malnutrition diagnosis codes to inpatient hospital claims OIG report A-03-17-00010